In　order　to　reduce　the　seismic　response　of　structures,　a　sort　of　viscous　damper　is　developed　by　using　a　silicon-based　polymer　material　as　the　viscous　medium　which　more　energy　can　he　expended　when　the　damper　works.　The　expressions　of　hysteresis　loops　and　dynamic　stiffness　of　the　damper　are　also　discussed.　The　evaluating　criterion　of　energy　dissipation　capacity　for　designed　damper　is　developed,　and　the　calculational　method　of　the　parameter　is　given　on　the　basis　of　experimentation.　Some　superior　features　are　proved　through　the　experiments　on　the　damper,　such　as　plump　hysteresis　loops,　simple　structure,　no　leakage　of　viscous　medium,　self-protection.